UD5 Toolkit
Semaphore Flag Translator - Online Signal Code Converter
Translate text into semaphore flag positions and decode semaphore back to letters. Interactive animated flags. For scouts and maritime fans.
Educational Tools - School & Teaching
99+ toolsTangram Puzzle - Online Drag & Match Shapes
Drag the seven tangram pieces to form a target silhouette. Multiple puzzles. Develop spatial thinking. All canvas interactions.
Periodic Table Explorer - Online Element Facts & 3D Model
Browse a beautifully designed periodic table with electron shell visualization and key facts. Click any element to learn more. Offline ready.
ASL Fingerspelling Practice - Online Random Words Quiz
Shows a random short word and displays animated ASL fingerspelling letters. Type what you see. Improve receptive skills.
Scale of the Universe - Online Zoom from Planck to Galaxy
Zoom through sizes from the Planck length to the observable universe. Educational and awe‑inspiring visualization.
Text to Anki CSV - Online Flashcard Converter
Format a list of Q&A pairs and export as a CSV ready for Anki import. Simple line‑based template. Local.
FizzBuzz Interactive Tester - Online Coding Classic
Run the classic FizzBuzz with custom rules. See the output for any range. A beginner programmer's playground.
Flame Test Colors - Online Element Identification Chart
Click a metal ion to see the characteristic flame color and wavelength. Useful for analytical chemistry reference.
Function Graph Plotter - Online Math Visualizer 2D
Plot one or more mathematical functions f(x) on a 2D canvas. Zoom, pan, and see intersections. Great for calculus and algebra. Purely client‑side.
Mental Math Trainer - Online Timed Arithmetic
Solve random arithmetic problems under a time limit. Track your score and improve mental calculation. No data collected.
Elephant Toothpaste Demo Calculator - Online Reaction Ratios
Find safe mixing ratios for the classic elephant toothpaste demonstration. Volume adjustments for different container sizes.
Easter Date Finder - Online Computus Algorithm for Any Year
Find the date of Easter Sunday for any given year. Learn about the computus algorithm. Simple and accurate.
Promise State Viewer - Online Check Resolve & Reject
Create promises that resolve or reject after a delay. See state changes and chain .then/.catch. Debug async code.
Polygon Name Finder - Online How Many Sides?
Enter a number of sides (3‑100) and get the correct polygon name (triangle, hectogon). Fun geometry reference.
Signed Magnitude Converter - Online Negative Binary Numbers
Encode decimal integers into signed magnitude binary representation and decode back. Learn computer arithmetic.
PRNG Validator - Online Check Randomness Pattern
Paste a list of numbers to visually check uniformity, mean, and simple pattern analysis. Educational tool for statistics and RNG.
Polygon Centroid Calculator - Online Center of Mass
Find the centroid (center of mass) of any convex polygon by entering vertex coordinates. Useful for physics and design.
Electron Configuration Writer - Online Orbital Diagram Tool
Get the full electron configuration and orbital box diagram for any element. Learn the Aufbau principle. Fast and local.
Bias Detector Tool - Online Check Text for Subjective Language
Analyze text for subjective and emotionally charged words. Helps identify potential bias in writing. Purely heuristic, local operation.
Radiation Converter - Online Gray Rad Rem & Sievert
Convert between units of absorbed dose and equivalent dose (Gray, Rad, Rem, Sievert). Educational and reference. Local calculation.
Regex Visualizer - Online Railroad Diagram Generator
Enter a regular expression and see a visual railroad diagram explaining the pattern. Learn and debug regex.
Telescope FOV Simulator - Online Eyepiece & View Preview
Select telescope and eyepiece parameters to see the field of view circle on a simulated night sky image.
Spirograph Simulator - Online Hypocycloid Drawing Tool
Create beautiful Spirograph patterns by adjusting circle radii and pen position. Change colors and save as PNG. Relaxing math art.
Handwriting Worksheet Generator - Online Traceable Letters
Create custom traceable handwriting worksheets with name or sentence. Print in dotted font. Great for teachers and parents.
Alphabet of Elements - Online A‑Z by Chemistry Symbol
See all elements sorted alphabetically by symbol. Picture and atomic weight. Beautifully styled static list.
Day of the Week Calculator - Online Find Weekday from Date
Find what day of the week any past or future date falls on. Uses Zeller’s congruence. Fun historical reference tool.
Interactive Periodic Table - Online Chemistry Reference
An interactive periodic table of elements with detailed properties, electron configuration, and images. Excellent educational resource. All static data.
Flexbox Playground - Online CSS Flex Layout Generator
Visually experiment with Flexbox container and item properties. See the layout update in real time and copy the CSS. Learn by doing, fully interactive.
Binary to Text Converter - Online Decode Bits to String
Paste binary sequences and convert them back to readable text. Supports space-separated and 8-bit formatted strings. Quick encoding reconversion.
Bohr Model Viewer - Online Atom Electron Shells
Click any element to see its Bohr model with electrons orbiting in shells. Beautiful, educational diagram.
Molecular Geometry Viewer - Online VSEPR 3D Sketch
Select bonding and lone pairs to see the predicted shape (trigonal bipyramidal, octahedral). Static diagrams.
CSS Grid Playground - Online Interactive Layout Builder
Experiment with CSS Grid properties visually. Add rows, columns, and areas. See the grid in action and copy the code.
pH Scale Explorer - Online Interactive Acid Base Chart
Drag a slider along the pH scale to see examples of solutions at that pH and the concentration of H⁺ and OH⁻ ions.
Roman Numeral Date Converter - Online MMXXVI Style
Convert any date into Roman numerals (day‑month‑year) for tattoos or special occasions. Clean and local.
Constellation Sky Viewer - Online Star Map & Mythology
Click on a constellation to see its star pattern and read the Greek mythology behind it. Beautiful CSS illustration.
Polygon Area Calculator - Online Irregular Shape Tool
Calculate the area of an irregular polygon by entering its vertex coordinates. Uses the shoelace formula. Pure math.
Chemical Equation Balancer - Online Stoichiometry Solver
Enter an unbalanced chemical equation and get the balanced coefficients instantly. Supports parentheses and ions. All local JavaScript algebra.
SQL JOIN Visualizer - Online Interactive Venn Diagrams
See interactive Venn diagrams for SQL JOINs: INNER, LEFT, RIGHT, FULL, CROSS. Understand set theory visually. Local static site.
Fraction Calculator - Online Add Subtract Multiply Divide
Perform arithmetic on fractions and get simplified results. Handles mixed numbers and improper fractions. Step-by-step display. Educational and precise.
Probability Calculator - Online Odds & Combinatorics Tool
Compute probability for simple events, as well as permutations and combinations (nPr, nCr). Useful for statistics and game theory. Browser-based math.
Units of Measurement Reference - Online Quick Guide
Search and browse a comprehensive table of SI units and common imperial conversions. For students and engineers.
Password Strength Story - Online Visual Narrative
Evaluate password strength through a short interactive story where each character set adds lines to a narrative. Educational fun.
Julian Date Converter - Online Calendar to JD
Convert a Gregorian calendar date to its Julian Day Number and vice versa. Used in astronomy and mainframe computing.
Virtual Microscope - Online Biology Slide Viewer
View pre‑loaded virtual microscope slides of onion cells, leaf epidermis, etc. Zoom and pan like a real microscope.
Tessellation Maker - Online M.C. Escher Style Tiling
Create a simple tessellation by deforming a square or triangle and repeating it across the canvas. Hypnotic patterns.
3D Perspective Box Drawer - Online Isometric Cube Tool
Draw a 3D box or room interior by dragging vanishing points. Great for learning perspective drawing. Export as image.
Kanji Stroke Order - Online Japanese Character Animator
Paste a Kanji and watch it drawn stroke by stroke with numbered sequence. Excellent for learners. Static data set.
Rock Cycle Interactive Diagram - Online Geology Model
Click through the rock cycle to see how each rock type transforms into another. Animated arrows and descriptions.
IQR Calculator - Online Interquartile Range & Box Plot
Enter a dataset to compute Q1, median, Q3, IQR, and highlight outliers. Visual box plot generated in canvas.
Bayes' Theorem Calculator - Online Probability Update Tool
Easily compute posterior probabilities given prior, likelihood, and marginal likelihood. Visual diagram. All local.
Pi Digits Viewer - Online Scrolling Infinite π
Scroll through thousands of pre‑computed digits of π. Search for a specific string of digits. For math lovers.
Magic Square Generator - Online Create n x n Constant Sum Grid
Generate magic squares of odd order (3x3, 5x5, …). See the sum constant and verify rows, columns, diagonals. Educational math toy.
Conway's Game of Life - Online Cellular Automaton Simulator
Run Conway's Game of Life on a canvas grid. Draw patterns, start/stop the evolution, and adjust speed. A mesmerizing zero‑player simulation.
Pythagorean Theorem Calculator - Online Right Triangle Solver
Enter two sides of a right triangle and get the third. Also gives area and perimeter. Simple and visual.
Online Scientific Calculator - Free Advanced Math Tool
Full-featured scientific calculator with trigonometric, logarithmic, and exponential functions. Clean interface and keyboard support. No installation required.
Data Structure Visualizer - Online Array, Stack, Queue
Add, remove, push, pop items and watch the data structure change visually. Supports arrays, stacks, and queues. For CS students.
Parts‑of‑Speech Tagger - Online Text Analyzer
Paste a sentence and see each word tagged with its part of speech (noun, verb, adjective). Local rule‑based analysis.
Pixel Data to BMP Generator - Online Raw Image Builder
Enter RGB values row by row and create a tiny BMP file. Understanding bitmap headers. Geeky developer tool.
CSS Box Model Visualizer - Online Interactive Margin Padding
Adjust margin, border, padding, and content sizes interactively and see the rendered box model. Get the exact CSS. Teach or learn layout.
Pathfinding Visualizer - Online A*, Dijkstra & BFS Grid
Draw walls on a grid and watch A*, Dijkstra, or BFS find the shortest path. Interactive animation. Learn graph traversal.